The Mentor: Diddy. The Protégé: Usher.

7. The Mentor: Diddy. The Protégé: Usher.

When Usher signed to LaFace Records as a young boy he was given Sean Combs, then known as Puff Daddy, as a mentor. Usher contributed his smooth vocals to Diddy's noughties hit 'I Need a Girl, Part I' - and apparently Diddy took a 14-year-old Usher to parties.